Apparatus for sampling fluids flowing in a production well

ABSTRACT

In the preferred embodiments of the invention disclosed herein, new and improved fluid-investigating tools adapted for positioning in a production well are respectively provided with a selectively closed chamber adapted to entrap a representative sample of the well fluids flowing past the tool so that the fluid phases of different densities will become segregated. The tools are uniquely arranged to provide surface signals which are representative of the density of the segregated fluid phases at discrete intervals in the sample chamber for determining the volumetric proportions and densities of the well fluids.

k OR

United States Patent [191 Nicolas et al.

3/1972 Glenn, Jr. 73/611 R APPARATUS FOR SAMPLING FLUIDS 3,650,148

FLOWING IN A PRODUCTION WELL [75] Inventors: Yves Nicolas, Versailles; Andr I .Landaud, Maisons Alford, both of Primary Exammerderry Myracle prance Attorney, Agent, or Firm-Ernest R. Archambeau, Jr.; William R. Sherman; Stewart F. Moore [73] Assrgnee: Schlumberger Technology Corporation, New York, NY.

[22] Filed: Nov. 15,1972

[21] Appl. No.: 306,759 [57] ABSTRACT Related U.S. Application Data Q [63] Continuation-impart of Ser. No. 220,764, Jan. 26, the pfefrred embodlrlnents of the invention 197z, bando closed herein, new and 1mproved fluid-investigating tools adapted for positioning in a production well are [30] Foreign Application P i it D t respectively provided with a selectively closed chamber adapted to entrap a representative sample of the .l .28,l97l F ..7.27

, an fame I O well flu1ds flowing past the tool so that the flu1d phases 521 U.S. c1. 73/152 73/6l.l R of different densities will becOme segregated- The [51] Int. Cl EZlb 47/00 10015 are niquely arranged to provide surface signals [58] Field of Search H 73/61 R 6L1 R 152 32 which are representative of the density of the segre- 7 gated fluid phases at discrete intervals in the sample chamber for determining the volumetric proportions 5 References Cited and densities of the well fluids.

UNITED STATES PATENTS 3,365,945 H1968 Parks 73/223 28 Claims, 9 Drawing Figures 53" fi; 3e

Pmmwm n 3.323.133

SHEET 2 OF 5 v AC POWER 4 4 SUPPLY T g 67 LOW-PASS O/v/OER RECORDER FILTER 68 FREQ/ HIGH-PASS VOLTAGE FILTER cO/vvERTER 7 \77 70 51 Oc POWER SUPPLY 5 9 55 4 A 7 J PULSE W54 60 FL/P- FLOP GENERATO 0 r v Q; 56 L 62 FLIP-FLOP 0 GATE 4 RC 3 Q c/Rcu/T 57 g $212 2 53 STEPP/NG T MOTOR 30 l l HIGH-PASS J v 1 FILTER r AMP 52 l I =H= 51 1 I 49 L 1 PAIENTEDmamQu 3.828.133.

SHEET 3 BF 5 17' v FIG. 4

DENSITY WATER f 37 27 OIL GAS GAS /48 O/L 19' WATER 77.3,

J I9 I FIG. 6

PAINTED-M3019" 3.826.133

SHEET a 0F 5 FIG. 8

APPARATUS FOR SAMPLING FLUIDS FLOWING IN A PRODUCTION WELL This application is a continuation-in-part of our copending application Ser. No. 220,764 now abandoned, filed Jan. 26, 1972.

Various techniques have, of course, been employed heretofore for determining the phase mixture and nature of the fluids being produced from various depths in a production well. For example, such determinations are often made by successively trapping individual samples at various depths of interest in a well bore and returning the sampling tool to the surface for examination of each sample. It will, of course, be recognized that such samples are often unrepresentative of the true phase composition or mixture of the production fluids flowing at the sampling depth. Moreover, since it requires considerable time to secure a number of individual samples, changing well conditions during a prolonged sampling operation will often make it difficult to properly correlate the results of such multiple tests.

Another typical fluid-investigating tool is provided with a selectively expansible packer and is so arranged that when the tool is positioned at a selected depth in a well bore, the upwardly flowing well fluids will be diverted through the sampling chamber containing typical electrical sensors for continuously indicating the phase composition of the production fluids. Alternatively, tools of a similar design are often arranged for selectively trapping a sample of the flowing production fluids. After the different fluids have segregated, measurements are made from the surface which are indicative of the location of the interface between the phases so that the proportion of each phase composing the trapped sample can be readily determined. It will, however, be appreciated that such measuring tools present significant flow restrictions which may unduly modify the flow conditions of the well under investigation so as to affect the accuracy of these measurements. Moreover, the measurements obtained with measuring tools of this nature are often subject to error at high flow rates.

The determination of the flow rates of each of the several fluid phases is especially complicated since the lighter phases of the flowing fluids move faster than the heavier phases. Thus, it is particularly difficult to make a complete analysis of flowing production fluids. Nevertheless, it is known that the flow rates of each of the fluid phases can be determined if the densities and phase composition or mixture of the flowing production fluids can be accurately measured.

Accordingly, it is an object of the present invention to provide new and improved fluid-measuring apparatus for accurately determining the phase composition as well as the density of each fluid phase in multiphase connate fluids being produced from a production well without significantly altering the normal flow conditions in the well bore.

This and other objects of the present invention are attained by arranging a tool with body means having a reduced cross-sectional area for assuring the relatively undisturbed passage of production fluids thereby when the tool is suspended by an electrical cable in a flowing arranged to be rapidly moved to a position for cooperation with the body means for selectively trapping the fluids in an enclosed fluid-segregating chamber of selected dimensions. In two embodiments of the present invention, selectively controlled displacement means arranged to displace segregated connate fluids in succession from the chamber are cooperatively associated with position-signaling means and stationary densityresponsive means for providing surface indications which are representative of the volumetric proportions as well as the density of the connate fluids trapped in the chamber. In an alternative embodiment of the new and improved fluid-measuring apparatus of the present invention, selectively controlled displacement means arranged for passing density-responsive means through the enclosed fluid chamber are cooperatively associated with position-signaling means to provide successive surface indications characteristic of the density of the segregated fluids at different levels in the chamber as well as their respective volumetric proportions.

The novel features of the present invention are set forth with particularity in the appended claims. The invention, together with further objects and advantages thereof, may be best understood by way of the follow-' ing description of exemplary apparatus employing the principles of the invention as illustrated in the accompanying drawings, in which:

FIGS. 1 and 2 schematically illustrate the operation of one embodiment of a new and improved fluidmeasuring tool arranged in accordance with the principles of the present invention;

FIG. 3'shows one preferred embodiment of surface and downhole electronic circuitry for the measuring tools of the present invention;

FIG. 4 depicts a typical surface record provided by the new and improved tool shown in FIGS. 1 and 2;

FIG. 5 illustrates an alternative embodiment of a fluid-measuring tool of the present invention;

FIG. 6 portrays a surface record such as may be obtained with the new and improved tool of FIG. 5;

FIGS. 7 and 8 respectively depict the operation of still another embodiment of a fluidmeasuring tool arranged in accordance with the principles of the present invention; and

FIG. 9 shows an alternative embodiment of surface and downhole circuitry for operating the new and improved tool shown in FIGS. 7 and 8.

Turning now to FIG. 1, a new and improved fluidmeasuring tool 10 arranged in accordance with the present invention is depicted as it will appear when suspended by a typical electrical cable 11 in a cased well bore 12 below a production string (not shown) and ad jacent to a formation interval 13 from which connate fluids 14 are being produced through one or more perforations as at 15. As is typical where the connate fluids 14 are composed of two or more immiscible fluid phases (i.e., water, oil and gas), one of these phases will generally be a continuously flowing phase in which the other phases are flowing in the form of discrete bubbles or drops as at 16.

As illustrated in FIGS. 1 and 2, the preferred embodiment of the new and improved tool 10 includes body means preferably arranged as spaced upper and lower enlarged-diameter housings 17 and 18 which are longitudinally aligned and coupled together by an elongated body 19 having a limited cross-sectional area and an overall length of selected dimensions for presenting only minimal obstruction and disruption to the normal upward flow of the connate fluids 14 through the well bore 12. An elongated sleeve 20 is slidably mounted on the tool and cooperatively arranged for selective movement between an elevated position around the upper housing (as depicted in FIG. 1) and a lower position straddling the two enlarged housings l7 and 18 (as depicted in FIG. 2). Fluid seals, such as O-rings 21 and 22, are cooperatively arranged on the enlarged housings 17 and 18 for fluidly sealing the annular space or enclosed chamber 23 defined around the body 19 when the sleeve 20 is in its lower position.

In keeping with the objects of the present invention, actuating means 24 are disposed in spaced chambers 25 and 26 in the upper housing 17 and operatively arranged to rapidly shift the sleeve 20 to its chamberclosing position for collecting representative samples of the connate fluids l4 flowing past the new and improved fluid-measuring tool 10. As best seen in FIG. 1, the actuating means 24 include an axially aligned elongated threaded shaft 27 which is suitably journalled between the end walls 28 and 29 of the chamber 26 and coupled to a selectively operable stepping motor 30 in the chamber 25. The actuating means 24 further include a nut 31 which is threadedly coupled to the shaft 27 and restrained from rotating in relation to the housing 17 by a hook-shaped latch 32 which is pivotally mounted, as at 33, on the nut and slidably disposed within a longitudinal slot 34 in the housing wall. To releasably secure the sleeve 20 in its elevated position, the latch 32 has an outstanding finger or projection 35 on its lower end which is slidably disposed within the elongated housing slot 34 and cooperatively arranged for selective positioning under an inwardly projecting lug 36 on the upper end of the sleeve. Biasing means, such as a stout compression spring 37 engaged between the upper end of the sleeve 20 and a shoulder 38 on the upper housing 17, are cooperatively arranged for quickly driving the sleeve toward its lower position whenever the latch 32 is pivoted inwardly to withdraw the projection 35 from under the lug 36.

It will be appreciated that since the nut 31 cannot rotate in relation to the upper housing 17, rotation of the shaft 27 will be effective for selectively carrying the nut either upwardly or downwardly along the threaded shaft according to the rotational direction of the stepping motor 30. Accordingly, the upper end 39 of the latch 32 is extended upwardly and outwardly from the pivot 33 and adapted to be selectively engaged with the end wall 28 upon upward travel of the nut 31. Thus, upon contacting the end wall 28, the latch 32 will be pivoted inwardly (counterclockwise as viewed in FIG. 1) for withdrawing the latch finger 35 from its sleeveretaining position under the lug 36 thereby releasing the sleeve 20 for rapid downward movement to its chamber-closing position by the compressed spring 37.

The actuating means 24 are further arranged to selectively return the sleeve 20 from its lower chamberclosing position (FIG. 2) to prepare the tool 10 for the subsequent collection of a fluid sample. To accomplish this, the upper surface of the lug 36 is shaped to define an inclined camming surface 40 which is adapted to be contacted by the latch finger 35 when the sleeve 20 is in its lower position and as the nut 31 approaches the lower end wall 29. Thus, upon downward travel of the nut 31, the latch 32 will be momentarily pivoted inwardly by the camming surface 40 so that continued downward travel of the nut will enable the latch finger to then be urged outwardly under the lug 36 by biasing means such as the unbalanced weight of the latch or a spring 41. Once the latch 32 is re-engaged with the lug 36, the sleeve 20 will be returned to its elevated chamber-opening position by rotating the stepping motor 30 as required for raising the nut 31 along the shaft 27.

Accordingly, it will be appreciated that when the sleeve 20 is in its elevated position depicted in FIG. 1, rotation of the stepping motor 30 in one direction will raise the nut 31 sufficiently for engaging the upper latch end 39 with the upper housing wall 28 and tilting the latch 32 inwardly to release the sleeve for rapid travel to its lower position. After the sleeve 20 is in its chamber-closing position, counter-rotation of the stepping motor 30 will progressively carry the nut 31 downwardly along the shaft 27 for re-engaging the latch finger 35 under the lug 36 as the nut nears the lower end wall 29. Then, by reversing the stepping motor 30, the sleeve 20 will be returned to its elevated position as the nut 31 travels back up the shaft 27 toward the upper housing wall 28. Return of the sleeve 20 to its elevated position will, of course, be effective for recompressing the spring 37 to enable the actuating means 24 for subsequent operation.

As previously mentioned, it is essential to the present invention that the new and improved fluid-measuring tool 10 be especially arranged for capturing representative samples of the connate fluid 14 flowing upwardly in the well bore 12 past the tool. Thus, in addition to cooperatively arranging the actuating means 24 to rapidly shift the sleeve 20 to its chamber-closing position, the elongated body member 19 is sized to present a minimum obstruction to the passage of the connate fluids 14 past the tool 10 when the sleeve is in its elevated position. In this manner, there will be little or no modification of the flow conditions around the tool 10 so that truly representative samples of the connate fluids 14 will be trapped in the chamber 23 upon the rapid closure of the sleeve 20. To accomplish this, the diameter of the body member 19 is reduced to the extent permitted by the structural design of the tool 10 and the length of the reduced member is selected for minimizing the effects of the fluid turbulence created by the cross-sectional changes at the junctions of the reduced member and the enlarged housing sections 17 and 18. In an exemplary embodiment of the tool 10 which had a maximum outer diameter of about 43-min to permit ready passage of the tool through small-diameter production strings, it was found that satisfactory performance was obtained with the reduced member 19 having a diameter of about ZO-mm and an overall length of about 30cm. By way of contrast, it was found that performance of this exemplary tool was significantly affected when the length of the reduced body 19 was only about 20-cm.

Once a representative sample of the connate fluids 14 has been captured within the sample chamber 23, it is, of course, necessary to allow the entrapped fluids to segregate in the chamber in accordance with their respective densities before their volumetric proportions and composition can be determined. The new and improved tool 10 is, therefore, cooperatively arranged for providing indications at the surface which are representative of the density of the segregated fluids at spaced intervals along the length of the chamber 23 so that the volumetric proportions of each of the entrapped fluids as well as their respective densities can be accurately determined. It will, of course, be appreciated that these measurements will be dependent upon retaining the entrapped fluids in their segregated condition within the sample chamber 23.

Accordingly, as best seen in FIG. 1, the tool further includes selectively controlled displacement means 42 including an annular piston 43 which is movably mounted around the elongated body 19 and slidably fitted within the sleeve 20 for selectively displacing the segregated fluids in succession from the cham ber 23 and into contact with a density-responsive sensor 44 in a measuring chamber 45 arranged in the lower housing 18 between fluid passages 46 and 47. Elongated rods, as at 48, are coupled between the nut 31 and the piston 43 and cooperatively arranged for slowly moving the piston downwardly through the chamber 23 after the sleeve 20 is in its lower position and as the nut is carried downwardly along the threaded shaft 27 by selective rotation of the stepping motor 30. It will, of course, be recognized that as the nut 31 is carried upwardly to return the sleeve 20 to its elevated position,

the elongated rods 48 will also return the piston 43 to the position illustrated in FIG. 1.

In the preferred embodiment of the fluid-sampling tool 10, the density sensor 44 is an electromechanically oscillated hollow cylinder which, as fully described in US. Pat. No. 3,225,588, is cooperatively associated with exciter and detector windings 49 and 50 as well as a phase-shifting amplifier 51 for producing output signals having a frequency which is representative of the density of the fluid then passing through the measuring chamber 45. As will subsequently be explained with reference to FIG. 3, the density sensor 44 is coupled to the cable 11 by a high-pass filter 52 for supplying continuous density signals as the piston 43 is progressively moved through the sample chamber 23 to slowly discharge the entrapped fluids through the measuring chamber 45 to the exterior of the tool 10.

It will be appreciated that although the signals provided by the density sensor 44 will be indicative of the character of the segregated fluids asthey are successively displaced from the sample chamber 23, these output signals taken alone will be insufficient for accurately determining the volumetric proportions of the segregated fluids. Thus, as best seen in FIG. 3, circuit means 53 are respectively arranged on the tool 10 and at the surface for controlling the rotational direction of the stepping motor 30 as well as for producing additional surface indications or records which are representative of the movement or successive positions of the piston 43 as it progressively displaces the segregated fluids from the sample chamber 23. It will, of course, be recognized that the relative positions of the piston 43 within the chamber 23 will be directly related to the volumetric proportions of the segregated fluids which have been displaced from the sample chamber at each position of the piston.

As illustrated in FIG. ,3, the downhole portion of the circuit means 53 include a pulse generator 54 that is selectively controlled by a bistable multivibrator or flipflop 55 and cooperatively arranged for supplying either negative or positive output pulses to the stepping motor 30 by a gate 56 which is itself selectively controlled by a flip-flop 57. Thus, when the pulse generator 54 is, for example, producing positive output pulses, the stepping motor 30 will be driven in one rotational direction so long as the gate 56 is enabled. Conversely, when the pulse generator 54 is developing negative output pulses, the stepping motor 30 will be driven in the opposite rotational direction. In either case, the output pulses are coupled to the electrical cable 11 by means of a low-pass filter 58 for providing surface signals which are representative of the incremental positions of the piston 43 as the stepping motor 30 successively moves the piston upwardly and downwardly in the tool 10.

To control the polarity of the output pulses of the pulse generator 54 and, as a result, the rotational direction of the stepping motor 30, a pair of contactactuating switches 59 and 60 (FIGS. 1 and 3) are respectively mounted on the upper and lower end walls 28 and 29 and cooperatively adapted for alternate actuation by the nut 31 only at the limits of its travel along the shaft 27. As shown in FIG. 3, the switches 59 and 60 are coupled to a DC power supply 61 for alternatively supplying control signals to the set and reset inputsof the flip-flop 55 whenever the nut 31 respectively reaches its upper and lower limits of travel. It will, of course, be appreciated that once a first control signal is selectively applied to one of the control inputs of the flip-flop 55, the output polarity of the pulse generator 54 will remain unchanged until a second control signal is subsequently applied to the other control input of the flip-flop 55 as the nut 31 reaches the opposite extreme of its travel.

To control the application of the output pulses of the generator 54 to the stepping motor 30, a second pair of contact-actuated switches 62 and 63 (FIGS. 1 and 3) are respectively mounted adjacent to or commonly housed with the first pair of switches 59 and 60 so that the upper and lower switches in each pair will be respectively closed simultaneously as the nut 31 alternately reaches its upper and lower limits of travel. As shown in FIG. 3, the switches 62 and 63 are paralleled and both are coupled to the reset input of the flip-flop 57. The DC power supply 61 is coupled to the input of the paralleled switches 62 and 63 by a R-C circuit 64 having a long time constant. The power supply 61 is also coupled to the set input of the flip-flop 57 by a capacitor 65. Thus, upon the application of a DC voltage to the R-C circuit 64 and the capacitor 65, the capacitor will immediately supply a control pulse to the set input of the flip-flop 57; but the R-C circuit will delay the DC control signal until the initial travel of the nut 31 opens whichever one of the two switches 62 or 63 the nut was holding closed so that the control signal will not be supplied to the reset input of the flip-flop 57 until the other of these two switches is subsequently closed when the nut completes its travel. This delay will, therefore, enable the nut 31 to travel in one direction along the full length of the shaft 27 and then halt the stepping motor 30 when the delayed control signal is supplied to the reset input of the flip-flop 57 for disabling the gate 56.

Accordingly, to operate the new and improved tool 10, the sleeve 20 and the nut 31 are initially located in their lower positions as the tool is lowered into the well bore 12. Once the tool 10 islocated at a desired depth, a switch 66 in the surface circuitry 63 is closed to energize the downhole DC power supply 61. With the sleeve 20 and the nut 31 in their lower positions, the lower switches 60 and 63 will, of course, be closed and the upper switches 59 and 62 will be open at this time. Thus, when the DC power supply 61 is energized, a DC control signal will be simultaneously supplied to the reset input of the flip-flop 55 and to the set input of the flip-flop 57. Although the switch 63 is closed, the R-C circuit 64 will prevent this control signal from being supplied to the reset input of the flip-flop 57 before the switch 63 is opened by the upward travel of the nut 31. The R-C circuit, 64 will, however, become slowly charged. The application of the control signal to the reset input of the flip-flop 55 will be effective for operating the pulse generator 54 to produce output pulses of the proper polarity for rotating the stepping motor 30 as required for elevating the nut 31 along the shaft 27 so as to return the sleeve 20 to its elevated position. Application of the control signal to the set input of the flip-flop 57 will also enable the gate 56 so that the stepping motor 30 will operate; and output signals representative of the upward travel of the piston 43 will be supplied from the pulse generator 54 to the cable 11 by way of the low-pass filter 58 to indicate that the tool is properly operating.

Once the nut 31 has been carried to the upper limit of its travel along the threaded shaft 27, the upper switches 59 and 62 will be closed for simultaneously reversing the polarity of the output pulses from the pulse generator 54 and supplying the aforementioned delayed control signal from the R-C circuit 64 to the reset input of the flip-flop 57. This latter action will, of course, immediately disable the gate 56 and thereby halt further rotation of the stepping motor 30. it will, of course, be recognized that upon operation of the latch 32, the sleeve will be released for return to its sample-trapping position and the nut 31 will be stopped at its upper limit of travel.

When the sleeve 20 and nut 31 reach their elevated positions, the tool 10 will, of course, be in position for securing a representative fluid sample. Thus, once it is desired to measure the density of a sample, the surface switch 66 will be opened and then closed again. Reenergization of the DC power supply 61 will be effective for resuming the production of the reverse polarity output pulses from the pulse generator 54 as well as for supplying a new control signal by way of the capacitor 65 to the flip-flop 57 for re-enabling the gate 56. Hereagain, this second control signal will be delayed by the R-C circuit 64 to prevent its application to the reset terminal of the flip-flop 57 until after the upper switch 62 has opened so that the gate 56 will remain enabled until the nut 3l ultimately reaches the lower limit of its travel and closes the lower switch 63.

The output signals from the density sensor 44 are supplied to the surface by way of the electrical cable 11. Similarly, the output signals of the pulse generator 54 representative of the incremental positions of the piston 43 are also supplied to the surface by way of the cable 11. The surface portion of the circuitry 53 is, therefore. arranged to include a low-pass filter 67 which is coupled to a recorder 68 by a pulse divider 69 to produce a record which is indicative of the sequential positions of the piston 43 as it is moved up and down. Similarly, a high-pass filter 70 is included in the surface portion of the circuitry 53 and coupled to the recorder 68 by way of a frequency-to-voltage converter 71 for producing a simultaneous record which is representative of the density of the fluid then in contact with the density sensor 44. If desired, an indicator 72 is provided to indicate the progress of the nut 31.

Turning now to FIG. 4, a typical record 73 is shown as may be produced during the operation of the tool 10 in a well bore, as at 12, in which water, oil and gas are flowing. As depicted, a density curve 74 is produced which varies in accordance with the respective densities of the multiphase fluids which are displaced through the measuring chamber 45. Of equal importance, it will be noted that the record 73 will also include a series of equally spaced marks 75 which are respectively representative of the incremental positions of the piston 43 as it successively displaces the segregated connate fluids through the measuring chamber 45. Since the longitudinal displacement of the piston 43 is directly related to the volume of the fluids being displaced from the sample chamber 23 and into the measuring chamber 45, the volumes of each of the segregated connate fluids in the sample chamber can be readily determined. Thus, the record 73 will clearly indicate the relative proportions as well as the densities of the several fluids.

it will be noted that the upper portion of the curve 74 includes a portion (as at 76) which is representative of the density of the fluid (water in this instance) that is initially trapped in the measuring chamber 45. To be certain that a precise measurement is obtained, it has been found that the volume of the measuring chamber 45 should preferably be made equal to the volume of the inverted space 77 defined by the lowermost end of the sleeve 20 and the lower face of the piston 43 when the sleeve is in its elevated position. As a result, since this inverted space 77 will invariably trap an unrepresentative volume of lighter connate fluids and the measuring chamber 45 will trap the heaviest fluid, the piston movement required to expel the unwanted fluid from the measuring chamber will be equal to the distance between the lower face of the piston 43 and the lower end of the sleeve 20. This will mean that when the piston 43 reaches the lower limit of its travel, the entire volume of the representative sample will have been displaced through the measuring chamber 45 and the lighter fluids which were initially trapped in the inverted space 77 will now be located in the measuring chamber. It should be noted that by arranging a check valve 78 in the passage 47, the measurement chamber 45 will be initially filled with the heaviest fluid and any lighter fluids therein will escape by way ofthe passage 46. To facilitate the return of the piston 43 when it and the sleeve 20 are initially being moved upwardly, a second check valve (not shown) similar to the check valve 78 but reversed to operate in the opposite direction can be arranged in the lower housing 18 for admitting well bore fluids into the sample chamber 23 until the lower end of the sleeve has been disengaged from the seal 22.

Turning now to FIG. 5, an alternative embodiment is shown of a fluid-measuring tool 10' which is also arranged in accordance with the principles of the present invention. Inasmuch as this alternative tool 10' is substantially similar to the fluid-measuring tool 10, the equivalent elements of the two tools are identified by the same reference numerals and it is believed necessary to describe only the significant differences between these two tools.

As will be noted by a comparison of FIGS. 1 and 5, the tool 10' is cooperatively arranged to eliminate the piston 43 and the measuring chamber 45 described above in relation to the tool 10. Instead, the displacement means 42 are cooperatively arranged so that a density sensor 44', such as a typical ceramic or crystal oscillator, is successively passed through the segregated connate fluids entrapped in the sample chamber 23. As illustrated in FIG. 5, the density sensor 44 is dependently coupled to one or more rods 48 which are mounted on the nut 31' in the same manner as the rods 48 carrying the piston 43 in the tool 10.

The operation of the tool is, of course, generally similar to the operation of the tool 10. By way of distinction, however, once the sleeve is released for movement to its chamber-closing position, the density sensor 44 is instead passed through the length of the sample chamber 23 for successively obtaining the desired density measurements as the nut 31 is moved downwardly along the threaded shaft 27'. This difference will, of course, produce a density curve 74' as shown on the record 73' in FIG. 6 which is essentially reversed from the density curve 74 shown on the record 73 in FIG. 4. The spaced marks 75' will, of course, be representative of the incremental displacement of the sensor 44'. Since the sensor 44 moves downwardly in the chamber 23' the initial measurements obtained with the tool 10 will be indicative of the density of the lighter phases such as gas and the final measurements will be indicative of the density of the heaviest phase such as water. This will also mean that the initial unrepresentative density measurements will be of the lighter phases trapped in the inverted space just above the lower end of the sleeve 20' when it is in its elevated position. Hereagain, the upper portion 76' of the density curve 74 can be appropriately interpreted to disregard this meaningless initial measurement.

It will, of course, be recognized by those skilled in the art that the various moving parts of the fluid-measuring tools 10 and 10 are completely exposed to debris, suspended particulate matter, or other contaminating substances which are often present in flowing well fluids. Thus, should there be, for example, an accumulation of some solid well bore material such as sand, debris, or the like either around the elongated body 19 or between the sleeve 20 and the complementary exterior surfaces of the housings l7 and 18, the continued operation of the tool 10 (or the tool 10') could possibly be impaired, if not altogether halted, until the tool was removed and cleaned. Similarly, should such contaminating substances build up excessively around either the latch 32 or the shaft 27 or collect between adjacent coils of the sleeve-actuating spring 37, it will be recognized that the operation of the tools 10 and 10' will be correspondingly affected.

Accordingly, to correct problems such as these, a new and improved fluid-measuring tool 100 is preferably arranged as depicted in FIGS. 7 and 8 and sized and proportioned in a similar or identical fashion as the tools 10 and 10'. Inasmuch as it is readily apparent that the tool 100 is similar in many respects to the tool 10, it is believed unnecessary to describe in detail the similar or identical corresponding features of the tools 10 and 100.

i As illustrated in FIGS. 7 and 8, the preferred embodiment of the new and improved tool 100 includes body means having spaced upper and lower enlargeddiameter housings 101 and 102 which are tandemly joined by an elongated body 103 of reduced crosssectional area for minimizing the obstruction to the normal upward flow of the well bore fluids. An elongated sleeve 104 is slidably mounted on the tool and cooperatively arranged for selective movement between an elevated position (as seen in FIG. 7) and a lower sample-trapping position straddling the two enlarged housings 101 and 102 (as depicted in FIG. 8) where the sleeve-defines an annular space or enclosed chamber 105 around the elongated body 103.

As was the case with the tools 10 and 10' of the present invention, the tool 100 further includes actuating means 106 for rapidly shifting the sleeve 104 to its chamber-closing position to selectively collect representative samples of the connate fluids flowing past the new and improved fluid-measuring tool 100. As best seen in FIG. 7, the actuating means 106 include an axially aligned elongated threaded shaft 107 which is suitably arranged and journalled in the housing 101 and coupled to a selectively operable stepping motor 108 in a chamber 109 in the upper housing. The actuating means 106 further include a nut 110 which is threadedly coupled to the shaft 107 and restrained from rotating in relation to the housing 101 by a longitudinal spline 111 on the housing wall which is slidably received by a complementary slot on the nut. Since the nut l10-cannot rotate in relation to the upper housing 101, rotation of the shaft 107 will be effective for selectively carrying the nut either upwardly or downwardly along the threaded shaft according to the rotational direction of the stepping motor 108.

The tool 100 further includes selectively controlled displacement means 112 including an annular piston 113 which is movably mounted around the elongated body 103 and slidably fitted within the sleeve 104 for selectively displacing the segregated fluids in succession from the chamber 105 and into contact with a density-responsive sensor 114 in a measuring chamber 115 arranged in the lower housing 102 between fluid passages 116 and 117. Elongated rods, as at 118, are coupled between the nut 110 and the piston 113 and cooperatively arranged for moving the piston upwardly and downwardly as the nut is carried along the threaded shaft 107 by selective rotation of the stepping motor 108.

In the preferred embodiment of the fluid-sampling tool 100, the density sensor 114 is an electromechanically oscillated hollow cylinder which, as previously described with respect to the tools 10 and 10', is cooperatively associated with exciter and detector windings 119 and 120 in the lower housing 102 for producing output signals representative of the densities of the segregated fluids being successively displaced through the measuring chamber 115. As will subsequently be explained with reference to FIG. 9, the density sensor 114 is coupled to the cable 121 supporting the tool 100 for supplying continuous density signals as the piston 113 is progressively moved through the sample chamber 105 to slowly discharge the entrapped fluids through the measuring chamber 115 to the exterior of the tool 100. Hereagain, as previously" described with reference to the space 77 in the tool 10, the volume of the measuring chamber 115 is preferably made equal to the volume of the similar inverted space defined by the lower end of the sleeve 104 when it is in its elevated position.

One significant difference between the tool 100 and the tool 10 (as well as the tool 10') is that the actuating means 106 also include biasing means, such as a stout compression spring 122, cooperatively enclosed within the upper housing 101 to better adapt the new and improved tool 100 for operation in debris-bearing well bore fluids. Thus, to selectively couple the spring 122 to the sleeve 104 for rapidly driving it to its closed position as well as for returning the sleeve to its open position and re-energizing the compression spring, the actuating means 106 further include a spring support member 123 which, in its preferred embodiment, is arranged as a spaced pair of annular plates 124 and 125 movably disposed within the sleeve above and below the piston 113 and coupled to one another as by two or more stiff rods, as at 126, which are slidably fitted in complementary longitudinal passages through the piston. To sealingly engage the piston 113 within the sleeve 104 as well as to provide a fluid seal around the rods 126, a flat disc-like sealing member 127 of a stiff elastomeric material is mounted on the lower face of the piston.

As best seen in FIG. 7, when the sleeve 104 is in its elevated sample-admitting position, the spring 122 is compressed between the upper housing 101 and the upper annular plate 124; and the lower annular plate 125 is engaged with an inwardly directed shoulder 128 arranged around the lower end of the sleeve. To releasably secure the sleeve 104 against uncontrolled downward movement by the force of the spring 122, a generally circular or somewhat oval-shaped latch member 129 pivotally mounted in an upright position in a longitudinal recess on the piston 113 is provided with an outstanding upwardly facing projection 130 cooperatively arranged on one side of the latch for selective engagement with a downwardly-facing shoulder on the sleeve such as that defined by an inwardly opening recess or circumferential groove 131 formed around the interior of the lower end of the sleeve above the shoulder 128. Biasing means such as a coiled compression spring 122 are provided for normally biasing the latch 132 in a clockwise direction (as viewed in the draw ings) for carrying the projection 130 upwardly into latching engagement within the groove 131 whenever the latch member is free to rotate and is positioned adjacent to the sleeve groove. To normally retain the latch 129 in its latching position illustrated in FIG. 7, a cam surface, such as a flat 133, is formed on the opposite edge of the latch member from the outwardly projecting finger 130 and cooperatively positioned in relation to the transverse width or diameter of the elongated body member 103 to prevent rotation of the latch member so long as the flat cam surface is in touching engagement with the body member.

Accordingly, it will be appreciated that once the outstanding latch projection 130 is confined in the sleeve groove 131, the flat surface 133 will be parallel to and engaged with the adjacent side of the body 103 for preventing rotation of the latch member 129 from its latching position. With the latch 129 so engaged, it will be recognized that operation of the motor 108 for selectively rotating the shaft 107 so as to raise the nut 110 and the piston 113 will be effective to elevate the sleeve 104 to its elevated position and thereby compress the spring 122. Thus, to selectively release the sleeve 104 for movement by the spring 122 to its lower sampletrapping position, the body member 103 is recessed, as by a circumferential groove 134, at a selected upper lo cation thereon which coincides with the position of the latch 129 when the piston 113 and the sleeve have reached their uppermost positions as depicted in FIG. 7. Similarly, to permit the latch 129 to be rotated by the spring 132 so as to again bring the projection into latching engagement within the groove 131, a second recess or circumferential groove is arranged at a selected lower location on the body 103 coinciding with the position of the latch when the sleeve 104 and the piston 113 are each in their lowermost positions. Thus, only when the piston 113 carries the latch 129 downwardly from its tilted position illustrated in FIG. 8, once the latch is adjacent to the lower recess 135, it will be rotated by the spring 132 to reengage the projection 130 within the sleeve groove 131. At all other positions of the piston 113, the pivoted latch 129 carried thereby will be retained against rotation by engagement of either the fiat 133 or, as shown in FIG. 8, the adjacent curved edge of the latch member with that portion of the body 103 lying between the two recesses 134 and 135. It should be noted that the spring support member 112 is cooperatively arranged to remove the force of the spring 122 from the piston 113 until after the latch 129 has tilted downwardly to disengage the projection 130 from the recess 131 and the spring 122 has shifted the sleeve 104 downwardly away from the latch.

Accordingly, it will be appreciated that when the sleeve 104 is in its elevated position depicted in FIG. 7, rotation of the stepping motor 108 in one direction will raise the piston 113 sufficiently for bringing the latch flat 133 adjacent to the upper latch recess 134 so that the latch 129 is then free to tilt downwardly to release the sleeve for rapid travel to its lower position. After the sleeve 104 is in its chamber-closing position, counter-rotation of the stepping motor 108 will progressively carry the piston 113 downwardly so that once the latch 129 is opposite the lower latch recess 135, the latch spring 132 will position the latch for re-engaging the latch finger 130 within the groove 131. Then, by reversing the stepping motor 30, once the latch 129 moves above the lower recess 135, the latch will be retained against rotation and the sleeve 104 will be raised to its elevated position as the piston 113 is returned to its position shown in FIG. 7. Return of the sleeve 104 to its elevated position will, of course, be effective for recompressing the spring 122 to enable the actuating means 106 for subsequent operation. Hereagain, by virtue of the lost-motion connection provided between the piston 113 and the spring support member 112, the compression force of the spring 122 is isolated from the latch member 129.

In keeping with the objects of the present invention, the new and improved tool 100 is particularly adapted for operation in debris-bearing or dirty well fluids as previously mentioned. Thus, in addition to arranging the sleeve-actuating spring 122 inside of the sleeve 104 so as to prevent the entrapment of debris or sediment between the coils of the spring, particular measures are also taken to assure that the sleeve will continue to move freely while subjected to contaminants in the well bore fluids. For example, as best seen in FIG. 7, two or more circumferentially spaced rollers, as at 136, are journalled on the upper housing 101 and cooperatively arranged to be in rolling contact with the internal surfaces of the sleeve 104. Similarly, two or more circumferentially-spaced rollers, as at 137, are also journalled on the piston 113 and adapted to be in rolling contact with the internal surfaces of the sleeve 104 whenever there is relative movement between the piston and sleeve. It will, of course, be appreciated that the rollers 136 and 137 will facilitate the upward and downward movements of the sleeve 104 in relation to the upper housing 101.

Other new and improved provisions are also made to assure the reliable operation of the tool 100 in even sediment-bearing well fluids. For instance, to permit only clean fluids to enter the space above the piston 113 which is enclosed by the sleeve 104, a port is provided near the upper end of the sleeve and blocked by a suitable filtering medium as at 138. Of even more signiticance, it will be noted that the upper end of the sleeve 104 is provided with a combination seal and scraper 139 which is preferably formed of a stiff elastomeric material. Thus, by shaping the member 139 as illustrated, as the sleeve 104 is returned upwardly to its elevated position, the leading edge of the scraper member will clear away sediment or other contaminants which might otherwise collect and tend to accumulate on the exterior of the upper housing 101 during the operation of the tool 100. Similarly, the outer and inner edges of the annular face seal 127 on the piston 113 will respectively serve as a scraper for clearing such contaminants from the interior of the sleeve 104 and from around the central body member 103 each time the piston is lowered in relation to the sleeve. As a result, it will be appreciated that the scraping action of the two members 127 and 139 will be highly effective in assuring the continued trouble-free operation of the new and improved tool 100.

As a further aid to trouble-free operation, the upper end of the lower housing 102 is chamfered as shown at 140 to at least minimize the risk that solid matter might accumulate on top of the lower housing and, in time, prevent sealing closure of the lower end of the sleeve 104 around the sealing member 141 on the lower housing. Similarly, to prevent entrance of debris and the like into the measuring chamber 115, a filtering medium 142 is arranged in the entrance of the fluid passage 116.

Although the circuitry shown generally at 53 in FIG.

3 could, of course, be employed to control the new and improved tool 100 and obtain records therefrom, it is preferred to employ the downhole and surface circuitry shown generally at 143 in FIG. 9 with the tool 100. In general, the circuitry 143 is adapted to control the motor 108 (which, in the preferred embodiment of the present invention, is a constant-speed two-phase motor) by selectively controlling its direction of rotation as required to initially carry the sleeve 104 and the piston 113 to their elevated positions and then, once the sleeve is released and has been shifted to its fluidtrapping position, to move the piston downwardly for displacing the entrapped fluids from the sample chamber 105. Means are further provided for signalling the travel of the piston 113 to determine the volumes of the several fluid phases as well as for providing measurements representative of the densities of the several fluid phases.

To accomplish this, the circuit means 143 is cooperatively arranged to include an AC power supply 144 at the surface which is coupled by way of the cable 121 and a gate 145 to a pair of gates 146 and 147 which are respectively coupled to the forward" and reverse terminals of the two-phase stepping motor 108. Thus,

so long as the gate is enabled, when the gate 146 is enabled, the stepping motor 108 will be driven in one rotational direction; and, conversely, when the gate 147 is enabled, the stepping motor 108 will be driven in the opposite rotational direction. In either case, a controllable counter-timer 148 is cooperatively arranged to operate so long as the motor 108 is operating for providing repetitive surface signals which are representative of the incremental positions of the piston 113 as the stepping motor successively moves the piston upwardly and downwardly in the tool 100.

To control the gates 146 and 147 and, as a result, the rotational direction of the stepping motor 108, a pair of contact-actuated switches 149 and 150 (FIGS. 8 and 9) are mounted in the upper housing 101 and cooperatively adapted for alternate engagement by the nut 110 only when it reaches the upper and lower limits of its travel along the shaft 107. As shown in FIG. 9, the switches 149 and 150 are coupled to a DC power supply 151 for alternatively supplying control signals to the set and reset inputs of a bistable multivibrator or flipflop 152 having its two outputs respectively coupled to the control inputs of the gates 146 and 147. It will, of course, be appreciated that once a first control signal is selectively applied to one of the control inputs of the flip-flop 152, only a selected one of the two gates 146 and 147 will be enabled until a second control signal is subsequently applied to the other control input of the flip-flop 152 as the nut 110 reaches the opposite extreme of its travel.

To control the application of AC power from the power supply 144 to the stepping motor 108, a second pair of contact-actuated switches 153 and 154 (FlGS. 8 and 9) are respectively mounted adjacent to or commonly housed with the first pair of switches 149 and 150 so that the upper and lower switches in each pair will be respectively closed simultaneously as the nut 110 alternately reaches its upper and lower limits of travel. As shown in FIG. 9, the switches 149 and 150 are paralleled and both are coupled to the reset input of a second bistable multivibrator or flip-flop 155. The DC power supply 151 is coupled to the input of the paralleled switches 149 and 150 by a R-C circuit 156 having a long time constant. The power supply 151 is also coupled to the set input of the flip-flop 155 by a capacitor 157. Thus, upon the application of a DC voltage to the R-C circuit 156 and the capacitor 157, the capacitor will immediately supply a control pulse to the set input of the flip-flop 155. The R-C circuit will, however, cooperate to delay the DC control signal until the initial travel of the nut 110 opens whichever one of the two switches 149 and 150 the nut was previously holding closed so that the control signal will not be supplied to the reset input of the flip-flop 155 until the other of these two switches is subsequently closed when the nut completes its travel. This delay will, therefore, enable the nut 110 to travel in one direction along the full length of the shaft 107 and then halt the stepping motor 108 when the delayed control signal is finally supplied to the reset input of the flip-flop 155 for disabling the gate 145.

The density-measuring sensor 114 operates in the same manner as previously described with respect to the tools 10 and 10' and by reference to FlG. 3. By way of contrast,'however, the piston-displacement measurements provided by the timer 148 are initiated by simultaneously closing a pair of ganged switches 158 and 159 which operate jointly to connect the power supply 144 to the downhole portion of the circuitry 143 as well as to apply a starting signal, V to the timer. This, of course, will start the timer 148 which continues to run until the flip-flop 155 operates to produce an output pulse at its output when the gate 145 is disabled. An output signal at the 0 output of the flip-flop 155 is sent to the surface by way of the cable 121 where it is detected, as by a detector 160, and supplied to the stop" input of the timer 148.

Accordingly, to operate the new and improved tool 100, the sleeve 104 and the nut 110 are initially located in their lower positions as the tool is lowered into the well bore. Once the tool 100 is located at a desired depth, the switches 158 and 159 in the surface portion of the circuitry 143 are closed to energize the downhole DC power supply 151. With the sleeve 104 and the nut 110 in their lower portions, the lower switches 150 and 154 will, of course, be closed and the upper switches 149 and 153 will be open at this time. Thus, when the DC power supply 151 is energized, a DC control signal will be simultaneously supplied to the reset input of the flip-flop 152 and, by way of the capacitor 157, to the set input of the flip-flop 155. Although the switch 154 is closed, the R-C circuit 156 will prevent this control signal from being supplied to the reset input of the flip-flop 155 before the switch 154 is opened by the upward travel of the nut 110. The R-C circuit 156 will, however, become slowly charged. Since the gate 145 is enabled by the control signal, the application ofthe control signal to the reset input ofthe flip-flop 152 will be effective for enabling the gate 146 to rotate the stepping motor 108 as required for elevating the piston 113 so as to return the sleeve 104 to its elevated position. Application of the control signal, V,,, to the start input of the timer 148 will, of course, be effective for producing output signals representative of the upward travel of the piston 113 to indicate that the tool 100 is properly operating.

Once the nut 110 has been carried to the upper limit of its travel along the threaded shaft 107, the upper switches 149 and 153 will be closed for simultaneously enabling the gate 147 and supplying the aforementioned delayed control signal from the R-C circuit 156 to the reset input of the flip-flop 155. This latter action will, of course, immediately disable the gate 145 and thereby halt further rotation of the stepping motor 108. It will, of course, be recognized that the sleeve 104 will be released for return to its sample-trapping position and the nut 110 will be stopped at its upper limit of travel.

When the sleeve 104 and nut 110 reach their elevated positions, the tool 100 will, of course, be in position for securing a representative fluid sample. Thus, once it is desired to measure the density of a sample, the surface switches 158 and 159 will be opened and then closed again. Since the switch 149 is now closed, re-energization of the DC power supply 151 will be effective for enabling the gate 147 as well as supplying a new control signal by way of the capacitor 157 to the flip-flop 155 for re-enabling the gate 145. Hereagain, this second control signal will be delayed by the R-C circuit 156 to prevent its application to the reset terminal of the flip-flop 145 until after the upper switch 153 has opened so that the gate 145 will remain enabled until the nut 110 reaches the lower limit of its travel and again closes the lower switch 154.

The record produced by the new and improved tool will, of course, be similar or identical to that produced by the tool 10 and depicted at 73 in FIG. 4. Thus, no further discussion is needed. It should also be noted that the tool 100 could also be modified along the lines of the tool 10' by substituting a density sensor, as at 44', for the piston 113. This would, of course, result in a record such as that shown at 73 in FIG. 6.

Accordingly, it will be appreciated that the present invention has provided new and improved fluidmeasuring tools which are especially arranged for accurately determining the relative proportions as well as the nature of multiphase connate fluids being produced from a production well. By arranging the bodies of these tools to present minimal obstruction to the normal flow of connate fluids in the well bore, these tools are particularly adapted to be disposed in a flowing production well without significantly altering the flow conditions. Moreover, by quickly trapping the flowing fluids in the sample chamber respectively provided on each of these tools, truly representative samples of the connate fluids will be captured for examination. As described, the unique combination of the selectively controlled displacement means with the density-measuring means and position-signaling means in these tools will provide accurate surface indications which are representative of the volumetric proportions of the several phases of the entrapped fluids as well as their respective densities.

While particular embodiments of the present invention have been shown and described, it is apparent that changes and modifications may be made without departing from this invention in its broader aspects; and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

What is claimed is:

l. Fluid-measuring apparatus adapted for determining the volumetric composition and character of mixed multiphase well fluids flowing through a well bore and comprising:

body means adapted for suspension in a well bore and having a reduced cross-sectional area for presenting minimum obstruction to the passage of well fluids flowing thereby;

a sleeve operatively arranged on said body means for movement between one position cooperable with said body means for defining an enclosed fluidsegregated chamber and another position for opening said chamber;

actuating means adapted for selectively moving said sleeve between its said positions to successively admit multiphase well fluids into said chamber and entrap samples thereof within said chamber for segregation in accordance with their respective densities;

density-responsive means cooperatively arranged for producing first electrical signals representative of fluid density;

displacement means cooperatively arranged for selectively producing relative movement between said density-responsive means and successive portions of segregated fluid samples trapped in said chamber to obtain successive first signals representative of their respective fluid densities; and

movement-responsive means cooperatively arranged for producing second dectrical signals representative of the relative movement between said displacement means and successive fluid portions to obtain successive second signals representative of the volumetric proportions of the segregated samples. 2. The fluid-measuring apparatus of claim 1 further including:

passage means coupled to said chamber; means for mounting said density-responsive means in a fixed location within said passage means; said displacement means include piston means adapted to be moved between successive positions within said chamber for displacing such successive fluid portions through said passage means past said density-responsive means to obtain said successive first signals; and said movement-responsive means are cooperatively associated with said piston means for obtaining said successive second signals as a function of said positions of said piston means. 3. The fluid-measuring apparatus of claim 1 wherein said displacement means include:

a member movably mounted within said chamber; said density-responsive means are mounted on said movable member for movement thereby between successive positions in said chamber for obtaining said successive first signals; and said movement-responsive means are cooperatively associated with said movable member for obtaining said successive second signals as a function of said positions of said density-responsive means. 4. The fluid-measuring apparatus of claim 1 wherein said actuating means include:

means operable from the surface for moving said sleeve from its said one position to its said other position, and means operable from the surface for moving said sleeve from its said other position to its said one position at a greater speed. 5. The fluid-measuring apparatus of claim 1 wherein said actuating means include:

first means selectively operable from the surface for moving said sleeve from its said one position to its said first means include a movable member movably mounted on said body means, motor means selectively operable from the surface for moving said movable member between spaced positions, and latch means mounted on said movable member and cooperatively arranged for latching engagement with said sleeve when said sleeve is in its said one position for carrying said sleeve from its said one position to its said other position upon movement of said movable member between one of its said spaced positions and another of its said spaced positions; and

said second means include spring means cooperatively arranged for urging said sleeve from its said other position to its said one position, and latchrelease means cooperatively arranged on said body means for releasing said latch means from said slleve upon movement of said movable member to its said other spaced position.

7. The fluid-measuring apparatus of claim 6 further including:

passage means coupled to said chamber;

means for mounting said density-responsive means in a fixed location within said passage means;

said displacement means include piston means coupled to said movable member for movement thereby between successive positions within said chamber for displacing such successive fluid portions past said density-responsive means to obtain said successive first signals; and

said movement-responsive means are cooperatively associated with said movable member for obtaining said sucessive second signals as a function of said sucessive positions of said piston means.

8. The fluid-measuring apparatus of claim 6 wherein said displacement means include:

means coupling said density-responsive means to said movable member for movement thereby between successive positions in said chamber for obtaining said sucessive first signals; and

said movement-responsive means are cooperatively associated with said movable member for obtaining said successive second signals as a function of said positions of said density-responsive means.

9. Fluid-measuring apparatus adapted for determining the volumetric composition and character of mixed multiphase well fluids flowing through a well bore and comprising:

a body adapted for suspension in a well bore and including an elongated member having a reduced cross-sectional area for presenting minimum obstruction to the passage of well fluids thereby;

means including a sleeve cooperatively arranged on said body for longitudinal movement between one position around said elongated member defining an enclosed fluid-segregating chamber and another position longitudinally displaced from said one position and permitting the relatively undistributed flow of well fluids around said elongated member;

actuating means adapted to selectively move said sleeve between its said positions for successively passing mixed multiphase well fluids around said elongated member and entrapping representative fluid samples within said chamber for segregation into discrete phase portions in accordance with their respective densities;

displacement means including piston means cooperatively arranged on said elongated member and adapted to be selectively moved through said chamber whenever said sleeve is in its said one position for sucessively displaced segregated fluid portions from said chamber;

density-measuring means including passage means in communication with said chamber and adapted to carry fluids displaced from said chamber, and density-responsive means in said passage means and adapted for producing first electrical signals at the surface representative of the densities of the segregated fluid portions as they are successively displaced from said chamber through said passage means; and

movement-responsive means cooperatively arranged to produce second electrical signals at the surface representative of the successive movement of said piston means through said chamber for determining the respective volumes of the segregated fluid portions.

10. The fluid-measuring apparatus of claim 9 wherein said actuating means include:

first means adapted for moving said sleeve from its said one position to its said other position, and second means adapted for moving said sleeve from its said other position to its said one position at a faster rate of movement than its rate of movement from its said one position to its said other position.

11. The fluid-measuring apparatus of claim 9 further including:

means adapted for recording said first and second electrical signals to provide a record representative of the volumetric proportions and densities of the segregated fluid portions successively displaced from said chamber.

12. F luid-measuring apparatus adapted for determining the volumetric composition and character of mixed multiphase well fluids flowing through a well bore and comprising:

a body adapted for suspension in a well bore and including an elongated member having a reduced cross-sectional area for presenting minimum obstruction to the passage of well fluids flowing thereby;

means including a sleeve cooperatively arranged on said body for longitudinal movement between one position around said elongated member defining an enclosed fluid-segregating chamber and another position longitudinally displaced from said one position permitting the relatively undisturbed flow of well fluids around said elongated member;

actuating means adapted to selectively move said sleeve between its said positions for successively passing mixed multiphase well fluids around said elongated member and entrapping representative fluid samples within said chamber for segregation into discrete phase portions in accordance with their respective densities;

density-measuring means including densityresponsive means adapted to be longitudinally moved through said chamber for producing first signals at the surface representative of the densities of the segregated fluid portions trapped in said chamber; and

movement-responsive means cooperatively arranged to produce second signals at the surface representative of the successive positions of said densityresponsive means within said chamber for determining the respective volumes of the segregated fluid portions.

13. The fluid-measuring apparatus of claim 12 wherein said actuating means include:

first means adapted for moving said sleeve from its said one position to its said other position, and second means adapted for moving said sleeve from its said other position to its said one position at a faster rate of movement than its rate of movement from its said one position to its said other position.

14. The fluid-measuring apparatus of claim 12 further including:

means adapted for recording said first and second electrical signals to provide a record representative of the volumetric proportions and densities of the ing the volumetric composition and character of mixed multiphase well fluids flowing through a well bore and comprising:

a body adapted for suspension in a well bore and including longitudinally spaced enlarged-diameter body members and a reduced-diameter body member coupled between said enlarged-diameter member;

a sleeve coaxially arranged on said body and adapted for longitudinal movement thereon between a first position straddling said enlarged-diameter member defining an enclosed fluid-segregating chamber around said reduced-diameter member and a second position on one of said enlarged-diameter members permitting the relatively-undisturbed flow of well fluids around said reduced-diameter member;

displacement means including piston means cooperatively arranged on said reduced-diameter member and adapted to be moved through said chamber whenever said sleeve is in its said first position for successively displacing segregated fluid samples from said chamber;

density-measuring means adapted for producing first electrical signals at the surface representative of the densities of the segregated fluid samples successively displaced from said chamber;

motor means on said body and adapted for selective operation in alternate rotational directions;

piston-moving means responsive to the rotation of said motor means in one rotational direction for selectively moving said piston means from an initial position through said chamber for successively displacing segregated fluid samples therefrom and responsive to the rotation of said motor means in the opposite rotational direction for shifting said sleeve from its said first position to its said second position as well as returning said piston means to said initial position;

actuating means selectively operable for shifting said sleeve from its said second position to its said first position; and

circuit means adapted for selectively operating said motor means and producing second electrical signals at the surface representative of the successive positions of said piston means in said chamber as a function of the volumetric proportions of the segregated fluid samples succesively displaced from said chamber.

16. The fluid-measuring apparatus of claim 15 wherein said actuating means include:

spring means adapted for biasing said sleeve toward its said first position, and latch means cooperatively arranged between said sleeve and said pistonmoving means for selectively releasing said sleeve for movement to its said first position whenever said sleeve is shifted to its said second position.

17. The fluid-measuring apparatus of claim 16 wherein said spring means include:

a coiled compression spring coaxially disposed around said one enlarged-diameter member and cooperatively arranged to be energized in response to movement of said sleeve to its said second positron.

19. The fluid-measuring apparatus of claim wherein said actuating means include:

spring means adapted for biasing said sleeve toward its said first position, and latch means releasably coupled to said sleeve and responsive to the movement of said piston means to said inital position for releasing said sleeve for movement from its said second position to its said first position.

20. The fluid-measuring apparatus of claim 19 wherein said spring means include:

a coiled compression spring coaxially disposed around said one enlarged-diameter member and cooperatively arranged to be energized in response to movement of said sleeve to its said second position.

21. The fluid-measuring apparatus of claim 19 wherein said spring means include:

a coiled compression spring coaxially disposed around said reduced-diameter member and cooperatively arranged between said one enlargeddiameter member and said piston means to be energized in response to the return of said piston means to said initial position.

22. The fluid-measuring apparatus of claim 21 wherein said compression spring is coaxially disposed within said sleeve.

23. The fluid-measuring apparatus of claim 15 further including:

means cooperatively arranged on said sleeve and adapted for removing foreign material from the exterior surfaces of said one enlarged-diameter member as said sleeve is shifted from its said first position to its said second position.

24. The fluid-measuring apparatus of claim 15 further including:

means cooperatively arranged on said piston means and adapted for removing foreign material from the interior surfaces of said sleeve when said sleeve is in its said first position and as said piston means move from said initial position.

25. The fluid-measuring apparatus of claim 15 further including:

means cooperatively arranged on said piston means and adapted for removing foreign material from the exterior surfaces of said reduced-diameter member as said piston means move from said initial position.

26. F luid-measuring apparatus adapted for determining the volumetric composition and character of mixed multiphase well fluids flowing through a well bore and comprising:

a body adapted for suspension in a well bore and including longitudinally spaced enlarged-diameter body members and a reduced-diameter body member coupled between said enlarged-diameter members;

a sleeve coaxially arranged on said body and adapted for longitudinal movement thereon between a first position straddling said enlarged-diameter members defining an enclosed fluid-segregating chamber around said reduced-diameter member and a second position on one of said enlarged-diameter members permitting the relatively undisturbed flow of well fluids around said reduced diameter member;

density-measuring means including densityresponsive means adapted for producing first electrical signals representative of fluid density;

motor means on said body and adapted for selective operation in alternate rotational directions;

first means responsive to the rotation of said motor means in one rotational direction for selectively moving said density-responsive means from an initial position through said chamber to obtain successive first signals representative of the fluid densities of segregated fluid samples trapped in said chamber and responsive to the rotation of said motor means in the opposite rotational direction for shifting said sleeve from its said first position to its said second position as well as returning said density-responsive means to said initial position;

actuating means selectively operable for shifting said sleeve from its said second position to its said first position;

circuit means adapted for selectively operating said motor means and producing second electrical signals at the surfaces representative of the successive positions of said density-responsive means in said chamber as a function of the volumetric proportions of the segregated fluid samples trapped therein.

27. The fluid-measuring apparatus of claim 26 wherein said actuating means include:

spring means adapted for biasing said sleeve toward its said first position, and latch means cooperatively arranged between said sleeve and first means for releasing said sleeve for movement to its said first position whenever said sleeve is shifted to its said second position.

28. The fluid-measuring apparatus of claim 26 wherein said circuit means include:

first circuit means coupled to said motor means and adapted for alternately rotating said motor means in each of said adapted for alternately rotating said motor means in each of said rotational directions, and second circuit means selectively operable from the surface and coupled to said first circuit means for controlling the rotational direction of said motor means. 

1. Fluid-measuring apparatus adapted for determining the volumetric composition and character of mixed multiphase well fluids flowing through a well bore and comprising: body means adapted for suspension in a well bore and having a reduced cross-sectional area for presenting minimum obstruction to the passage of well fluids flowing thereby; a sleeve operatively arranged on said body means for movement between one position cooperable with said body means for defining an enclosed fluid-segregated chamber and another position for opening said chamber; actuating means adapted for selectively moving said sleeve between its said positions to successively admit multiphase well fluids into said chamber and entrap samples thereof within said chamber for segregation in accordance with their respective densities; density-responsive means cooperatively arranged for producing first electrical signals representative of fluid density; displacement means cooperatively arranged for selectively producing relative movement between said density-responsive means and successive portions of segregated fluid samples trapped in said chamber to obtain successive first signals representative of their respective fluid densities; and movement-responsive means cooperatively arranged for producing second dectrical signals representative of the relative movement between said displacement means and successive fluid portions to obtain successive second signals representative of the volumetric proportions of the segregated samples.
 2. The fluid-measuring apparatus of claim 1 further including: passage means coupled to said chamber; means for mounting said density-responsive means in a fixed location within said passage means; said displacement means include piston means adapted to be moved between successive positions within said chamber for displacing such successive fluid portions through said passage means past said density-responsive means to obtain said successive first signals; and said movement-responsive means are cooperatively associated with said piston means for obtaining said successive second signals as a function of said positions of said piston means.
 3. The fluid-measuring apparatus of claim 1 wherein said displacement means include: a member movably mounted within said chamber; said density-responsive means are mounted on said movable member for movement thereby between successive positions in said chamber for obtaining said successive first signals; and said movement-responsive means are cooperatively associated with said movable member for obtaining said successive second signals as a function of said positions of said density-responsive means.
 4. The fluid-measuring apparatus of claim 1 wherein said actuating means include: means operable from the surface for moving said sleeve from its said one position to its said other position, and means operable from the surface for moving said sleeve from its said other position to its said one position at a greater speed.
 5. The fluid-measuring apparatus of claim 1 wherein said actuating means include: first means selectively operable from the surface for moving said sleeve from its said one position to its said other position, and second means responsive to movement of said sleeve to its said other position for moving said sleeve to its said one position.
 6. The fluid-measuring apparatus of claim 5 wherein: said first means include a movable member movably mounted on said body means, motor means selectively operable from the surface for moving said movable member between spaced positions, and latch means mounted on said movable member and cooperatively arranged for latching engagement with said sleeve when said sleeve is in its said one position for carryIng said sleeve from its said one position to its said other position upon movement of said movable member between one of its said spaced positions and another of its said spaced positions; and said second means include spring means cooperatively arranged for urging said sleeve from its said other position to its said one position, and latch-release means cooperatively arranged on said body means for releasing said latch means from said slleve upon movement of said movable member to its said other spaced position.
 7. The fluid-measuring apparatus of claim 6 further including: passage means coupled to said chamber; means for mounting said density-responsive means in a fixed location within said passage means; said displacement means include piston means coupled to said movable member for movement thereby between successive positions within said chamber for displacing such successive fluid portions past said density-responsive means to obtain said successive first signals; and said movement-responsive means are cooperatively associated with said movable member for obtaining said sucessive second signals as a function of said sucessive positions of said piston means.
 8. The fluid-measuring apparatus of claim 6 wherein said displacement means include: means coupling said density-responsive means to said movable member for movement thereby between successive positions in said chamber for obtaining said sucessive first signals; and said movement-responsive means are cooperatively associated with said movable member for obtaining said successive second signals as a function of said positions of said density-responsive means.
 9. Fluid-measuring apparatus adapted for determining the volumetric composition and character of mixed multiphase well fluids flowing through a well bore and comprising: a body adapted for suspension in a well bore and including an elongated member having a reduced cross-sectional area for presenting minimum obstruction to the passage of well fluids thereby; means including a sleeve cooperatively arranged on said body for longitudinal movement between one position around said elongated member defining an enclosed fluid-segregating chamber and another position longitudinally displaced from said one position and permitting the relatively undistributed flow of well fluids around said elongated member; actuating means adapted to selectively move said sleeve between its said positions for successively passing mixed multiphase well fluids around said elongated member and entrapping representative fluid samples within said chamber for segregation into discrete phase portions in accordance with their respective densities; displacement means including piston means cooperatively arranged on said elongated member and adapted to be selectively moved through said chamber whenever said sleeve is in its said one position for sucessively displaced segregated fluid portions from said chamber; density-measuring means including passage means in communication with said chamber and adapted to carry fluids displaced from said chamber, and density-responsive means in said passage means and adapted for producing first electrical signals at the surface representative of the densities of the segregated fluid portions as they are successively displaced from said chamber through said passage means; and movement-responsive means cooperatively arranged to produce second electrical signals at the surface representative of the successive movement of said piston means through said chamber for determining the respective volumes of the segregated fluid portions.
 10. The fluid-measuring apparatus of claim 9 wherein said actuating means include: first means adapted for moving said sleeve from its said one position to its said other position, and second means adapted for moving said sleeve from its said other position to its said one position at a faster rate of movement than its rate of movement from its said one posItion to its said other position.
 11. The fluid-measuring apparatus of claim 9 further including: means adapted for recording said first and second electrical signals to provide a record representative of the volumetric proportions and densities of the segregated fluid portions successively displaced from said chamber.
 12. Fluid-measuring apparatus adapted for determining the volumetric composition and character of mixed multiphase well fluids flowing through a well bore and comprising: a body adapted for suspension in a well bore and including an elongated member having a reduced cross-sectional area for presenting minimum obstruction to the passage of well fluids flowing thereby; means including a sleeve cooperatively arranged on said body for longitudinal movement between one position around said elongated member defining an enclosed fluid-segregating chamber and another position longitudinally displaced from said one position permitting the relatively undisturbed flow of well fluids around said elongated member; actuating means adapted to selectively move said sleeve between its said positions for successively passing mixed multiphase well fluids around said elongated member and entrapping representative fluid samples within said chamber for segregation into discrete phase portions in accordance with their respective densities; density-measuring means including density-responsive means adapted to be longitudinally moved through said chamber for producing first signals at the surface representative of the densities of the segregated fluid portions trapped in said chamber; and movement-responsive means cooperatively arranged to produce second signals at the surface representative of the successive positions of said density-responsive means within said chamber for determining the respective volumes of the segregated fluid portions.
 13. The fluid-measuring apparatus of claim 12 wherein said actuating means include: first means adapted for moving said sleeve from its said one position to its said other position, and second means adapted for moving said sleeve from its said other position to its said one position at a faster rate of movement than its rate of movement from its said one position to its said other position.
 14. The fluid-measuring apparatus of claim 12 further including: means adapted for recording said first and second electrical signals to provide a record representative of the volumetric proportions and densities of the segregated fluid portions successively displaced from said chamber.
 15. Fluid-measuring apparatus adapted for determining the volumetric composition and character of mixed multiphase well fluids flowing through a well bore and comprising: a body adapted for suspension in a well bore and including longitudinally spaced enlarged-diameter body members and a reduced-diameter body member coupled between said enlarged-diameter member; a sleeve coaxially arranged on said body and adapted for longitudinal movement thereon between a first position straddling said enlarged-diameter member defining an enclosed fluid-segregating chamber around said reduced-diameter member and a second position on one of said enlarged-diameter members permitting the relatively-undisturbed flow of well fluids around said reduced-diameter member; displacement means including piston means cooperatively arranged on said reduced-diameter member and adapted to be moved through said chamber whenever said sleeve is in its said first position for successively displacing segregated fluid samples from said chamber; density-measuring means adapted for producing first electrical signals at the surface representative of the densities of the segregated fluid samples successively displaced from said chamber; motor means on said body and adapted for selective operation in alternate rotational directions; piston-moving means responsive to the rotation of said motor means in one rotational direction for selecTively moving said piston means from an initial position through said chamber for successively displacing segregated fluid samples therefrom and responsive to the rotation of said motor means in the opposite rotational direction for shifting said sleeve from its said first position to its said second position as well as returning said piston means to said initial position; actuating means selectively operable for shifting said sleeve from its said second position to its said first position; and circuit means adapted for selectively operating said motor means and producing second electrical signals at the surface representative of the successive positions of said piston means in said chamber as a function of the volumetric proportions of the segregated fluid samples succesively displaced from said chamber.
 16. The fluid-measuring apparatus of claim 15 wherein said actuating means include: spring means adapted for biasing said sleeve toward its said first position, and latch means cooperatively arranged between said sleeve and said piston-moving means for selectively releasing said sleeve for movement to its said first position whenever said sleeve is shifted to its said second position.
 17. The fluid-measuring apparatus of claim 16 wherein said spring means include: a coiled compression spring coaxially disposed around said one enlarged-diameter member and cooperatively arranged to be energized in response to movement of said sleeve to its said second position.
 18. The fluid-measuring apparatus of claim 15 wherein said circuit means include: first circuit means coupled to said motor means and adapted for alternately rotating said motor means in each of said rotational directions, and second circuit means selectively operable from the surface and coupled to said first circuit means for controlling the rotational direction of said motor means.
 19. The fluid-measuring apparatus of claim 15 wherein said actuating means include: spring means adapted for biasing said sleeve toward its said first position, and latch means releasably coupled to said sleeve and responsive to the movement of said piston means to said inital position for releasing said sleeve for movement from its said second position to its said first position.
 20. The fluid-measuring apparatus of claim 19 wherein said spring means include: a coiled compression spring coaxially disposed around said one enlarged-diameter member and cooperatively arranged to be energized in response to movement of said sleeve to its said second position.
 21. The fluid-measuring apparatus of claim 19 wherein said spring means include: a coiled compression spring coaxially disposed around said reduced-diameter member and cooperatively arranged between said one enlarged-diameter member and said piston means to be energized in response to the return of said piston means to said initial position.
 22. The fluid-measuring apparatus of claim 21 wherein said compression spring is coaxially disposed within said sleeve.
 23. The fluid-measuring apparatus of claim 15 further including: means cooperatively arranged on said sleeve and adapted for removing foreign material from the exterior surfaces of said one enlarged-diameter member as said sleeve is shifted from its said first position to its said second position.
 24. The fluid-measuring apparatus of claim 15 further including: means cooperatively arranged on said piston means and adapted for removing foreign material from the interior surfaces of said sleeve when said sleeve is in its said first position and as said piston means move from said initial position.
 25. The fluid-measuring apparatus of claim 15 further including: means cooperatively arranged on said piston means and adapted for removing foreign material from the exterior surfaces of said reduced-diameter member as said piston means move from said initial position.
 26. Fluid-measuring apparatus adapted for determining the volumetric compOsition and character of mixed multiphase well fluids flowing through a well bore and comprising: a body adapted for suspension in a well bore and including longitudinally spaced enlarged-diameter body members and a reduced-diameter body member coupled between said enlarged-diameter members; a sleeve coaxially arranged on said body and adapted for longitudinal movement thereon between a first position straddling said enlarged-diameter members defining an enclosed fluid-segregating chamber around said reduced-diameter member and a second position on one of said enlarged-diameter members permitting the relatively undisturbed flow of well fluids around said reduced diameter member; density-measuring means including density-responsive means adapted for producing first electrical signals representative of fluid density; motor means on said body and adapted for selective operation in alternate rotational directions; first means responsive to the rotation of said motor means in one rotational direction for selectively moving said density-responsive means from an initial position through said chamber to obtain successive first signals representative of the fluid densities of segregated fluid samples trapped in said chamber and responsive to the rotation of said motor means in the opposite rotational direction for shifting said sleeve from its said first position to its said second position as well as returning said density-responsive means to said initial position; actuating means selectively operable for shifting said sleeve from its said second position to its said first position; circuit means adapted for selectively operating said motor means and producing second electrical signals at the surfaces representative of the successive positions of said density-responsive means in said chamber as a function of the volumetric proportions of the segregated fluid samples trapped therein.
 27. The fluid-measuring apparatus of claim 26 wherein said actuating means include: spring means adapted for biasing said sleeve toward its said first position, and latch means cooperatively arranged between said sleeve and first means for releasing said sleeve for movement to its said first position whenever said sleeve is shifted to its said second position.
 28. The fluid-measuring apparatus of claim 26 wherein said circuit means include: first circuit means coupled to said motor means and adapted for alternately rotating said motor means in each of said adapted for alternately rotating said motor means in each of said rotational directions, and second circuit means selectively operable from the surface and coupled to said first circuit means for controlling the rotational direction of said motor means. 